Re: NTLM HTTP Authentication is insecure by design - a new writeup by Amit Klein

From: 3APA3A (3APA3A_at_SECURITY.NNOV.RU)
Date: 07/19/05

  • Next message: Kerry Thompson: "Re: Installation of software, and security. . ." 
    Date: Tue, 19 Jul 2005 13:35:36 +0400
To: "Amit Klein (AKsecurity)" <aksecurity@hotpop.com>

    Dear Amit Klein (AKsecurity),

    --Monday, July 18, 2005, 9:40:32 PM, you wrote to bugtraq@securityfocus.com:

    AKA> NTLM HTTP Authentication
    AKA> (and possibly other connection-oriented
    AKA> HTTP authentication and authorization protocols)
    AKA> is insecure by design

     NTLM authentication is insecure by design for external authentication,
     because of "single signon" ideology. NTLM authentication can be used
     for NTLM proxy attack. For example, attacker who can hijack or spoof
     server connection with NTLM authentication can use this connection to
     access different Web server, mail server or file server with client's
     credentials. This is known for many years and was discussed for many
     times. Few years ago Internet Explorer was patched to use NTLM
     authentication only for local network zone. Local network are hosts
     with NetBIOS name (for example WEBSRV, excluded by default from proxy)
     and list of proxy exclusions.

     So, under default configuration, NTLM will not be used through proxy
     server, at least in Internet Explorer. 

    -- 
~/ZARAZA
http://www.security.nnov.ru/
  • Next message: Kerry Thompson: "Re: Installation of software, and security. . ."

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